Radio-picture-frequency chopper



1,525,549 c. F. JENKINS RADIO PICTURE FREQUENCY CHOPPER Filed Aug- 30, 1922 gwuew foi a Patented Feb, 10, 1925.

"UNITED-STATES PATENT oFncE.

CHARLES FRANCIS JENKINS. OF WASHINGTON, DISTRICT OF COLUMBIA, ASSIGNOR TO RADIO PICTURES CORPORATION, OF WASHINGTON, DISTRICT OF COLUMBIA, A-

CORPORATION.

RADIO-PICTURE-FREQUEN CY CHOPPER.

' Application.filed. August 30, 1922. Serial No. 585,318.

To all whom it may concern Be itknown that I, CHARLES FRANCIS JENKINS, a citizen of the .United States, residing at Washington, District of Columl bia, have invented certain new and useful Improvements in Radio-Picture-Frequency Choppers, of which the following is a specification.

This invention relates to details of meth-' '10 ods employed in the transmission of pic ture's-by-radio, and has for its object means for impressing a picture frequency upon a radio frequency in an inductive coupled circuit at the sending station. 1 The invention is diagrammatically illustrated in Fig. 1, accompanying this application, Fig. 2 being a detail of same. A is an illuminated picture; 7) a prismatic ring; 0 a lens; d a disc with equi-spaced openings peripherally arranged therein; d a motor 0111 rotating the'discs; and (5: a light-sensitive ce The rotation of the prismatic ring (the subject ofiPatent 1,385,255), or dlsc, b, hinges the pencil of light to cause it :0 cross the picture. The lens images the picture onto the light-sensitive cell. light is interrupted by the rotation of the V 6.180 d, the result being that the conductivity This pencil of of the cell is constantly varied, producing a rapidly fluctuating current in the. circuit of which it formsa part. This fluctuatin current can be used 1n inductively coupled circuits ofradio apparatus, and this is the principal object to be attained.

The varying light values encountered as the pencil of light sweeps across the picture causes fluctuating current values in the cell circuit frequencies which applicant and assistants have become accustomed to call picture frequencies.

This method of obtaining fluctuating current with picture frequencies thereon has been found tobe ver in producing results of high quality both in electrical circuits and in picture frequencies;

lVhat I claim is- In apparatus of the class described, the

impressed effective combination of a lighted surface, a light sensitive cell, a rotating light chopper therebetween, and a prism' between the light chopper and the lighted surface, the prism having aconstantly changing angle between its sides, all of the elements being in optical ali ent.

n testimony signature.

CHARLES FRANCIS JENKINS.

whereof I-have affixed my 

